Marley demonstrates unconditional love toward the growing Grogan family. When John and Jenny are exhausted and overwhelmed as new parents, Marley keeps up his end of the relationship, never letting John out of his sight (125). Marley loves John’s attention, but he continues to love John even when John is too busy or tired for him. When Jenny is at the hospital for nearly two weeks, Marley is John’s loyal companion at home with Patrick. He remains loyal to John even when John is too busy, distracted, and exhausted to return the attention. John never has to teach Marley loyalty or devotion because “he intuitively grasped from the start what it meant to be man’s best friend” (277).

It takes John several years to accept that Marley’s nature is not ideal or likely to change. As he accepts Marley for the dog he is rather than compare him to the dogs he’ll never be, John becomes Marley’s staunch protector and advocate. He carefully navigates Jenny’s postpartum ultimatum, keeping Marley in the family despite the anger Marley triggers in Jenny. John is willing to put in effort to help Marley remain part of the family. He also demonstrates unconditional love for Jenny during this difficult time.